Displaying 20 results from an estimated 2000 matches similar to: "multiple imputation based on a condition"
2010 Dec 11
1
randomForest: help with combine() function
I've built two RF objects (RF1 and RF2) and have tried to combine
them, but I get the following error:
Error in rf$votes + ifelse(is.na(rflist[[i]]$votes), 0, rflist[[i]]$votes) :
non-conformable arrays
In addition: Warning message:
In rf$oob.times + rflist[[i]]$oob.times :
longer object length is not a multiple of shorter object length
Both RF models use the same variables, although
2010 Dec 29
0
Simulating data and imputation
Hi,
I wrote a script in order to simulate data, which I will use for evaluating
missing data and imputation. However, I'm having trouble with the last part
of my script, in which a dataframe is constructed without missing values.
This is my script:
y1 <- rnorm(10,0,3)
y2 <- rnorm(10,3,3)
y3 <- rnorm(10,3,3)
y4 <- rnorm(10,6,3)
y <- c(y1,y2,y3,y4)
a1 <-rep(1,20)
a2
2011 Feb 07
1
multiple imputation manually
Hi,
I want to impute the missing values in my data set multiple times, and then
combine the results (like multiple imputation, but manually) to get a mean
of the parameter(s) from the multiple imputations. Does anyone know how to
do this?
I have the following script:
y1 <- rnorm(20,0,3)
y2 <- rnorm(20,3,3)
y3 <- rnorm(20,3,3)
y4 <- rnorm(20,6,3)
y <- c(y1,y2,y3,y4)
x1 <-
2003 Jul 27
1
multiple imputation with fit.mult.impute in Hmisc
I have always avoided missing data by keeping my distance from
the real world. But I have a student who is doing a study of
real patients. We're trying to test regression models using
multiple imputation. We did the following (roughly):
f <- aregImpute(~ [list of 32 variables, separated by + signs],
n.impute=20, defaultLinear=T, data=t1)
# I read that 20 is better than the default of
2003 Jun 16
1
Hmisc multiple imputation functions
Dear all;
I am trying to use HMISC imputation function to perform multiple imputations
on my data and I keep on getting errors for the code given in the help
files.
When using "aregImpute" the error is;
>f <- aregImpute(~y + x1 + x2 + x3, n.impute=100)
Loading required package: acepack
Iteration:1 Error in .Fortran("wclosepw", as.double(w), as.double(x),
2010 Aug 10
1
Multiple imputation, especially in rms/Hmisc packages
Hello, I have a general question about combining imputations as well as a
question specific to the rms and Hmisc packages.
The situation is multiple regression on a data set where multiple
imputation has been used to give M imputed data sets. I know how to get
the combined estimate of the covariance matrix of the estimated
coefficients (average the M covariance matrices from the individual
2012 Jul 05
0
Confused about multiple imputation with rms or Hmisc packages
Hello,
I'm working on a Cox Proportional Hazards model for a cancer data set that has missing values for the categorical variable "Grade" in less than 10% of the observations. I'm not a statistician, but based on my readings of Frank Harrell's book it seems to be a candidate for using multiple imputation technique(s). I understand the concepts behind imputation, but using
2009 Oct 21
0
multiple imputation with mix package
I am running into a problem using 'mix' for multiple imputation (over
continuous and categorical variables).
For the way I will be using this I would like to create an imputation
model on some training data set and then use this model to impute
missing values for a different set of individuals (i.e. I need to have
a model in place before I receive their information).
I expected that all
2008 Nov 26
1
multiple imputation with fit.mult.impute in Hmisc - how to replace NA with imputed value?
I am doing multiple imputation with Hmisc, and
can't figure out how to replace the NA values with
the imputed values.
Here's a general ourline of the process:
> set.seed(23)
> library("mice")
> library("Hmisc")
> library("Design")
> d <- read.table("DailyDataRaw_01.txt",header=T)
> length(d);length(d[,1])
[1] 43
[1] 2666
2007 Sep 26
1
using transcan for imputation, categorical variable
Dear all,
I am using transcan to impute missing values (single imputation). I have
several dichotomous variables in my dataset, but when I try to impute
the missings sometimes values are imputed that were originally not in
the dataset. So, a variable with 2 values (severe weight loss or
no/limited weight loss) for example coded 0 and 1, shows 3 different
values after imputation (0, 1 and 2).
I
2011 Oct 10
1
Multiple imputation on subgroups
Dear R-users,
I want to multiple impute missing scores, but only for a few subgroups in my
data (variable 'subgroups': only impute for subgroups 2 and 3).
Does anyone knows how to do this in MICE?
This is my script for the multiple imputation:
imp <- mice(data, m=20, predictorMatrix=pred, post=post,
method=c("", "", "", "",
2005 May 26
1
PAN: Need Help for Multiple Imputation Package
Hello all. I am trying to run PAN, multilevel
multiple imputation program, in R to impute missing
data in a longitudinal dataset. I could successfully
run the multiple imputation when I only imputed one
variable. However, when I tried to impute a
time-varying covariate as well as a response variable,
I received an error message, “Error: subscript out of
bounds.” Can anyone tell if my commands
2003 Dec 08
1
Design functions after Multiple Imputation
I am a new user of R for Windows, enthusiast about the many functions
of the Design and Hmisc libraries.
I combined the results of a Cox regression model after multiple imputation
(of missing values in some covariates).
Now I got my vector of coefficients (and of standard errors).
My question is: How could I use directly that vector to run programs such
as 'nomogram', 'calibrate',
2013 Apr 15
1
Imputation with SOM using kohonen package
I have a data set with 10 variables, and about 8000 instances (or
objects/rows/samples). In addition I have one more ('class') variable that
I have about 10 instances for, but for which I wish to impute values for.
I am a little confused how to go about doing this, mostly as I'm not
well-versed in it. Do I train the SOM with a data object that contains just
the first 10 variables
2005 May 04
3
Imputation
I have timeseries data for some factors, and some missing values are there in those factors, I want impute those missing values without disturbing the distribution of that factor, and maintaining the correlation with other factors. Pl. suggest me some imputation methods.
I tried some functions in R like aregImpute, transcan. After the imputation I am unable to retrive the data with imputed
2013 Feb 14
2
Plotting survival curves after multiple imputation
I am working with some survival data with missing values.
I am using the mice package to do multiple imputation.
I have found code in this thread which handles pooling of the MI results:
https://stat.ethz.ch/pipermail/r-help/2007-May/132180.html
Now I would like to plot a survival curve using the pooled results.
Here is a reproducible example:
require(survival)
require(mice)
set.seed(2)
dt
2018 Jan 27
0
Dovecot 2.3.0 assertion failure on LMTP delivery
Hi!
This is a bug in the new event code. Can you get a full gdb backtrace?
Aki
> On January 27, 2018 at 6:58 AM "J. Nick Koston" <nick at cpanel.net> wrote:
>
>
> Hi,
>
> We are seeing a frequent assertion failure on LMTP delivery with 2.3.0. This only appears to happen on CentOS/RHEL 7.
>
> Jan 24 08:30:58 smoker-devautomerge-c7-1 dovecot:
2005 Jul 08
2
missing data imputation
Dear R-help,
I am trying to impute missing data for the first time using R. The norm
package seems to work for me, but the missing values that it returns seem
odd at times -- for example it returns negative values for a variable that
should only be positive. Does this matter in data analysis, and/or is
there a way to limit the imputed values to be within the minimum and
maximum of the actual
2012 Mar 07
0
Multiple imputation using mice
Dear all,
I am trying to impute data for a range of variables in my data set, of which
unfortunately most variables have missing values, and some have quite a few.
So I set up the predictor matrix to exclude certain variables (setting the
relevant elements to zero) and then I run the imputation. This works fine if
I use predictive mean matching for the continous variables in the data set.
When I
2007 Jul 17
0
Multiple imputation with plausible values already in the data
Hello,
this is not really an R-related question, but since the posting guide does not
forbid asking non-R questions (even encourages it to some degree), I though I'd
give it a try.
I am currently doing some secondary analyses of the PISA (http://pisa.oecd.org)
student data. I would like to treat missing values properly, that is using
multiple imputation (with the mix package). But I am not